Ultrastructure and immunohistochemistry of the lateral prostate in aged rats

Abstract

Ultrastructural, histological, and immunohistochemical studies were performed on lateral prostates of 1) aged rats from different strains, 2) rats permitted different levels of sexual activity, and 3) castrated rats. Antibodies against the following proteins were used as immunohistochemical markers: SVS II from seminal vesicle, LP 28 from lateral prostate, acid phosphatase isoenzymes from ventral prostate, transglutaminase from coagulating gland, and a commercial monoclonal antibody against cytokeratin. SVS II is a marker of lateral prostatic secretion, while immunoreactions to LP 28 and acid phosphatase (pI 7.1) were cytoplasmic. In aged animals the amount of intracellular secretion is decreased, and focally metaplastic transformation can be visualized by using immunohistochemical markers. Epithelial ultrastructure varied considerably with experimental conditions. Intensive sexual activity resulted in increased polymorphism and increased number of secretory granules within the glandular cells, while castration was followed by a rapid loss of secretory material. Also, in rats older than 10 months, a reduction in the number of secretion granules was common. The epithelium developed a positive immunoreaction to transglutaminase antibodies that were not observed in juvenile glands. Cells, presumably macrophages, which had an intense immunoreactivity for transglutaminase, were increased in number both within and outside the prostatic acini of aged rats. The possible interaction between secretory SVS II, a substrate of transglutaminase, the release of this enzyme from macrophages or its reflux from coagulating glands, the spontaneous cellular exfoliation that is due to decreased androgen levels, and dietary noxae may be of importance in the development of lateral prostatic nonbacterial inflammation in aged rats.

A Retrospective Analysis of Background Lesions and Tissue Accountability for Male Accessory Sex Organs in Fischer-344 Rats

“…Spontaneous prostatitis occurs in the lateral lobe of aged rats and has been used as a model of nonbacterial prostatitis in humans (2,29,31). In our study, histopathological features of in ammation in the dorsolateral lobes were similar to those described for various strains of rats used for toxicity and carcinogenicity studies (2,4,6,8,12,31,39).…”

“…Spontaneous prostatitis occurs in the lateral lobe of aged rats and has been used as a model of nonbacterial prostatitis in humans (2,29,31). In our study, histopathological features of in ammation in the dorsolateral lobes were similar to those described for various strains of rats used for toxicity and carcinogenicity studies (2,4,6,8,12,31,39). Bacterial infection (6,31,39), endocrine in uence (6,24,29,39,42,51,52), immunological dysfunction (13,38,39), and stress (1, 6, 17) may be factors in development of prostatic in ammation.…”

Prepubertal Exposure to Compounds That Increase Prolactin Secretion in the Male Rat: Effects on the Adult Prostate1

“…However, the exact biochemical mechanism of this effect of PRL on lateral prostate inflammation remains to be determined. Moreover, the inflammation induced by ovine PRL appeared to be similar to the spontaneous prostatitis seen in the lateral prostates of aging Lewis, Copenhagen, and Wistar rats [31,32] that show the presence of a stromal mononuclear and luminal polymorphonuclear cellular infiltrate. In addition, this type of inflammation has been shown to precede fibromuscular growth [30], similar to that seen in human benign prostatic hyperplasia (BPH), with several studies indicating that neutrophils and lymphocytes are involved in fibroblast proliferation [33] and the synthesis of collagen [34].…”

Macrophage migration inhibitory factor in the human prostate: Identification and immunocytochemical localization

“…Macrophages populate the male reproductive tract and accessory glands, as they are abundantly found in the seminal fluid [27]. In the rat prostate, macrophages are localized within and outside the ducts [12,28]. Indeed, they represent an important mechanism of defense of the integrity and functionality of the gland.…”